1. Field of the Invention
This invention relates to deep-well vertical pumps. More particularly, relates to a system suitable to replace the discharge pipe string of a pump of said type, with the wall itself of said well.
2. The Prior Art
In general, there are presently three different types of deep-well pumps: those employing water for lubricating purposes, those lubricated by oil and those with underwater electric motor. Although certain substantial differences are present in the string or strings inside the well, coming from the wellhead into the aspirating end thereof, all said three types of pumps are coincident in the provision of a pipe string for conducting the fluid to be pumped from said well, e.g., water.
As it is well known in the art, a substantial portion of the pump costs is caused by the discharge pipe string, since said pipe must be formed from tubing the manufacture of which is subjected to high-precision standards as it is well known in the art. Since a drawn tube of the current type cannot be employed for these purposes, as the same serves both as a duct for the passing of the fluid towards the wellhead, and as an aligning means for the lower end of the string as well as for centering and connecting the sheath inside which there is the shaft and the bearing-supporting means, the tubing from which said discharge pipe string is made should be a very special one. Further, said string serves also as a conducting and supporting means, or simply for connecting and centering the shaft, when associated with a oil-lubricated pump, a water-lubricated pump or an underwater electric motor pump. Therefore, it should be highly desirable for a system to eliminate or suppress said discharge pipe string from said pumps.